Khan Academy
Khan Academy: Dalton's Atomic Theory
An article describing Dalton's atomic theory. Learn how this theory was the first attempt to describe a fundamental part of matter, atoms. Article also discusses where the theory is incorrect based on the knowledge we have today.
Science Struck
Science Struck: Plum Pudding Model
Describes J.J. Thomson's theory of atomic structure, called the 'Plum Pudding Model,' and how it was disproved by Ernest Rutherford.